Multi-piece cue sticks for playing pool are generally two piece sticks which consist of a lower shaft portion and an upper butt portion which can be assembled together for use or disassembled for transportation. Traditionally, the shaft and the butt are joined together with a two-piece coupling. The coupling usually includes a bushing having a standard female thread secured within the lower shaft portion of the cue stick and a rod having a mating male thread secured within the upper butt portion of the cue stick. The two portions of the cue stick are joined together by screwing the male thread of the rod into the mating female thread of the bushing until the end of the shaft portion of the cue stick contacts the end of the butt portion of the cue stick.
A problem with this type of coupling is that the two portions of the cue stick may not become concentric with each other when joined together. A non-concentric cue stick is undesirable because a non-concentric cue stick does not transfer energy to a pool ball as efficiently as a concentric stick and therefore, the pool ball is not hit as sharply. Additionally, assembling the cue stick together by screwing the threaded rod into the bushing is time consuming, therefore, making it unsuitable to disassemble the cue stick during a game for using only the shaft portion as a cue stick when there are space constraints or for jumping the cue ball.
Accordingly, there is a need for a multi-piece cue stick in which the various portions of the cue stick can be assembled together so that the pieces are concentric with each other. Furthermore, there is a need for the coupling of the multiple piece cue stick to be quickly engaged and disengaged so that the user can assemble and disassemble the cue stick quickly during a game.
The present invention provides a cue stick which includes a first stick portion coupled to a sleeve. The sleeve has a smooth inner diameter portion and a female coupling region. A second stick portion is coupled to a coupling rod. The coupling rod has a smooth, elongate tip which has a close fit with the smooth inner diameter of the sleeve and a male coupling region which engages the female coupling region of the sleeve for coupling the coupling rod to the sleeve.
In preferred embodiments, the female coupling region of the sleeve is an internal threaded region and the male coupling region of the coupling rod is a first external threaded region. The sleeve has an external threaded region for coupling the sleeve to the first stick portion. The coupling rod has a second external threaded region for coupling the coupling rod to the second stick portion.
In one preferred embodiment, the internal threaded region of the sleeve and the first external threaded region of the coupling rod are acme-type threads which are capable of being coupled together by twisting the sleeve and the coupling rod relative to each other.
The present invention provides a multi-piece cue stick which can be rapidly assembled and disassembled by twisting the various pieces relative to each other in one revolution or less. Additionally, the two pieces are joined together concentric with each other which enables the pieces to transfer energy more efficiently, thereby, allowing the user to hit a pool ball more sharply. Furthermore, the quick assembly and disassembly feature of the present invention cue stick allows cue sticks of two or more pieces to be assembled and disassembled during a game.